Are you blocking Office 365?

One of the funnier things that I run into every so often is when someone’s Office 365 implementation isn’t working because their firewall administrator is following the age-old practice of least permission. Definitely, a good way to keep your environment secure, and I wouldn’t tell you not to go down this path… but you probably want to tell your firewall admin to open up the IPs and URLs that are needed for your end users to make use of Office 365 appropriately.